|Spalding's campion, Spalding's catchfly, Spalding's silene|
The following Participating Institutions are custodians for this species in the CPC National Collection:
University Of Washington Botanic Gardens
The conservation of Silene spaldingii is fully sponsored.
Wendy Gibble contributed to this Plant Profile.
Spaldings catchfly (Silene spaldingii) is an herbaceous perennial of the intermountain grasslands and sagebrush-steppe of the Pacific Northwest. It is named after Henry Spalding, who first collected it in the mid 1800s near the Clearwater River of Idaho. Like many of its close relatives in the Pink Family, it earns its common name catchfly because all green portions of the plants are covered in dense sticky hairs that ensnare insects and dust. Unfortunately for this catchfly, the deep loamy soils typical of its preferred habitat were also preferred by white settlers for farming, and most of its habitat has been converted for agricultural use and, more recently, for urban development. On October 10, 2001, Spaldings catchfly was listed as a threatened species under the Endangered Species Act.
Spaldings catchfly blooms from mid-July through September an interesting phenomenon when one considers that this is the driest, hottest period of the year when water stress is highest. Another interesting habit of this species is that it can enter prolonged periods of dormancy in which individuals can remain entirely belowground for up to several years (Lesica and Steele 1994; Lesica 1997). Dormancy is thought to be correlated to periods of drought; however, this phenomenon is not well understood and more research is needed to understand what is involved in initiating and breaking dormancy (USFWS 2007).
Stems of Spaldings catchfly range in height from 8 to 24 inches and typically bear three to 20 flowers. Each plant typically has one stem growing from a persistent caudex (a thickened base of the stem located just belowground from which new stems arise), although multiple stems may sometimes occur. The cream-colored flowers are not very showy because most of the petal is enclosed within the calyx a green tube formed by the sepals. Each fertilized flower produces a capsule with up to 150 seeds.
Distribution & Occurrence
Spaldings catchfly occurs in bunchgrass or sagebrush dominated communities, in areas with higher soil moisture associated with swales or north to east facing slopes (Hill and Gray 2004). At higher elevations, Spalding's catchfly may occur on south facing slopes. Some populations are also found in open pine forests. Sites range in elevation between 1,380 and 5,300 feet and typically consist of deep loamy soils originating from wind deposits (loess soils), volcanic ash, and glacial deposits (USFWS 2007). Annual rainfall amounts range from 10 inches to 24 inches, with most of the rain occurring during the fall and winter months (Hill and Gray 2004). The prolonged summer drought precludes tree species from establishing, thus maintaining climax grassland communities (Daubenmire 1968). Dominant perennial grasses include Idaho fescue (Festuca idahoensis), Idaho fescue with rough fescue (Festuca scabrella), or Idaho fescue and bluebunch wheatgrass (Pseudoroegneria spicata) codominant (Hill and Gray 2004).
|There are approximately 24,500 individuals known from 110 occurrences; however, this count is approximate because the prolonged dormancy of this species makes population estimating and monitoring difficult. Of the 99 populations, 35 in the Channeled Scablands, 11 in the Intermontane Valleys, and 17 in the Palouse Grasslands, 14 in the Blue Mountain Basins, 22 in the Canyon Grasslands. Approximately 75 percent of all plants occur within 7 large populations (USFWS 2007).|
Conservation, Ecology & Research
The intermountain region of the Pacific Northwest typically experiences dry, hot summers and cool, moist winter months. Most plants cope with this climate by slow growth during the fall and winter months, significant growth during the spring months, and falling dormant by mid summer (Daubenmire 1970, Tisdale 1983). Spaldings catchfly does not follow this pattern - it emerges in late spring, grows throughout the summer months, flowers starting in July and continuing at some sites until early October, and is dormant during the winter (Hill and Gray 2004).
Fire likely plays an important ecological role in grasslands and shrub-steppe habitats where Spaldings catchfly occurs. It is thought that before fire suppression started, wildfires likely burned during the hot dry summers, but the frequency of historic fires is not known and hard to determine. Today, prescribed fires are used as a management tool, but the lands are burned during the cooler, fall months. Therefore, the fire regime of Spaldings catchfly has changed dramatically in the past century. The affects of prescribed fire on Spaldings catchfly and its habitat has been studied at several sites in Montana and Idaho (USFWS 2007). In all studies, adult plants survive fire, often producing more flowers in the subsequent year. However, seed set was lower at some sites, and seedling recruitment may also be impacted. Timing and intensity of the burn, in addition to characteristics of the site such as species composition, fuel loads and moisture content, are likely significant factors in determining how Spaldings catchfly responds to prescribed burning (Lesica 1997, Lesica 1999, Menke 2003, USFWS 2007).
Livestock grazing has played a significant role in shaping Spaldings catchflys habitat in the past century and has direct and indirect negative effects on survival of the species. Individual plants are damaged or destroyed by removal of flowers or seeds and by trampling. Trampling may also destroy some of its pollinators, including the ground-dwelling pollinator Bombus fervidus. Livestock can also cause significant habitat degradation that results in alteration of plant communities and increased invasive species colonization. These impacts are considered to be more severe in regions that did not historically host large, hooved animals such as the intermountain area west of the Rocky Mountains where Spaldings catchfly occurs (USFWS 2007).
Habitat loss and degradation due to urban and agricultural development and livestock grazing
Invasions by aggressive, nonnative plants
Changes in fire frequency and timing
Livestock grazing an
Demography studies have been conducted at the Dancing Prairie Preserve and at the Lost Trail National Wildlife Refuge in 2003 (USFWS 2007).
Effects of prolonged dormancy on fitness of individual plants were studied in Montana (Lesica and Crone 2007).
Germination studies have determined that cold stratification promotes germination, suggesting that seeds germinate in spring. Germination rates of 60 to 86 percent have been achieved with 30 days to 8 weeks of cold stratification (USFWS 2007).
A seedling recruitment study has shown that seedling survival is very sporadic, and significant recruitment occurs in 3 out of 13 years (USFWS 2007).
Genetic studies were completed in the early 1990s to evaluate genetic diversity within and across populations.(Baldwin and Brunsfeld 1995)
Ongoing surveys for new populations and long-term monitoring of known populations on state and federal lands and lands owned by The Nature Conservancy (USFS 2007).
Control and monitoring of invasive species and research on the effects of herbicide, fire, and biocontrols on controlling several invasive species including yellow starthistle (Centaurea solstitialis), sulfur cinquefoil (Potentilla recta), Canada thistle (Cirsium arvense), diffuse knapweed (Centaurea disffusa), and spotted knapweed (Centaurea maculosa) (USFS 2007).
Management plans have been prepared for several sites and plans for other sites are currently being drafted (USFS 2007).
A prescribed burning plan has been developed at The Nature Conservancys Dancing Prairie Preserve in Montana (USFS 2007).
Seeds from five large populations have been collected and stored in a seed bank (USFWS 2007). Additional collections are planned in 2008.
Land exchanges and acquisitions to preserve tracts of Spaldings catchfly habitat (USFWS 2007).
Determine population viabilities for Silene spaldingii populations.
Utilize existing key conservation areas and identify new key conservation areas with good habitat where new populations should be developed or where existing populations could be supplemented.
Determine the best techniques for creating new populations or supplementing existing populations of Silene spaldingii.
Conduct research essential to controlling and managing invasive nonnative plants within Silene spaldingii habitat.
Conduct research essential to managing livestock, wildlife, and insect herbivory at Silene spaldingii populations.
Conduct research to better determine the effects of fire on Silene spaldingii and identify when and where prescribed fire should occur, particularly outside of Montana.
Future seed collections should focus on all populations not identified as key conservation areas and coordinated so as to capture as much of the genetic variability as possible.
Daubenmire, R. 1970. Steppe vegetation of Washington. Technical Bulletin 62. Pullman, Washington. Washington State University, Washington Agricultural Experiment Station, College of Agriculture. 131p.
Franklin, J.F.; Dyrness, C.T. 1988. Natural vegetation of Oregon and Washington. Oregon State University Press, Corvallis, Oregon. 427p.
Hitchcock, C.L.; Cronquist, A. 1973. Flora of the Pacific Northwest. University of Washington Press, Seattle, Washington. 730p.
Hitchcock, C.L.; Cronquist, A.; Ownbey, M.; Thompson, J.W. 1964. Vascular plants of the Pacific Northwest, Part 2: Salicaceae to Saxifragaceae. University of Washington Press, Seattle, Washington. 597p.